The person coming home alone may value a message that does not demand an immediate reply.

Contact and obligation are easy to confuse. A message asking how someone is, when they are tired and walking through a dark front door, can arrive as one more thing to answer, while a note that plainly wants nothing back simply sits there being warm. The difference is whether the person has to produce something to receive your care.

Send the kind of message that closes itself. Tell them you were thinking of them, or say what made you laugh today, and add that no reply is needed. They will read it when they get in, and it will be a small light rather than another task.